Forest Service prairie may see bison again

Renée Thakali
Midewin National Tallgrass Prairie, U.S. Forest Service
April 12th, 2013 at 5:15PM

Today, roughly half-a-million bison dot the nation’s landscape, a far cry from the more than 20 to 30 million that once roamed much of North America.

And while they have not been part of the Forest Service’s Midewin National Tallgrass Prairie ecosystem for more than a century, the habitat here will soon be home for 20 to 30 of the animals, perhaps as early as December 2013.

The Midewin, the first national tallgrass prairie, covers 19,000 acres of the former Joliet Arsenal in northeastern Illinois. It is the largest piece of contiguous open space in the Chicago metropolitan area and is located just an hour’s drive from the Windy City.

“Establishing a herd of bison on Midewin will bring more visitors to the site to view these iconic symbols of our heritage,” said Wade Spang, supervisor on the Midewin.

It will also help enhance the local economy along the nearby historic U.S. Route 66.

Along with the bison herd, the proposal will also restore 1,200 acres of non-native grasslands to more desirable habitat for grassland birds by planting a diversity of native tallgrass species such as little bluestem, Indian grass and big bluestem.

The proposal also lays out a system of multi-use trails with elevated overlooks that will surround the bison pasture. Hiking trails will be within portions of it and only opened for trail use when bison are not present. Long-term plans include a visitor tram system that travels within the pastures.

“Scientific literature frequently refers to bison as a keystone species in the tallgrass prairie ecosystem,” said Spang. “This is a great opportunity for partners, especially universities who are interested in studying the effect of bison grazing when restoring grassland bird habitat.”

Keystone species have a disproportionately large effect on their environment. Bison have a couple of effects on prairie ecosystems as they graze and wallow. When they graze, their pattern is patchy, leaving a mosaic of grass heights and plant species, which benefits plant and animal diversity. In addition, grazing increases the cycling of nitrogen in the soil. As they wallow, bison increase plant and animal diversity. Soil compaction can aid in surface water retention as well, thereby providing habitat for aquatic species.